Field of the Invention
The present invention relates to a linear movement device comprising two or more linear movement units which are guided in a movable manner along a shared linear movement axis.
Background of the Invention
The linear movement device comprises a combined block- and individual drive, which is configured to move the two or more linear movement units both jointly as a block along the linear movement axis—in other words without movement relative to one another—and with movement relative to one another along the linear movement axis.
The linear movement units are preferably supports of pipetting ducts and thus part of a pipetting device. The present invention therefore also relates to a pipetting device comprising a linear movement device as disclosed in the following.
A block- and individual drive device of this type is known on pipetting devices comprising a plurality of pipetting ducts which can be moved both individually, separately from one another, and jointly in a block.
Deviating from the above-defined conventional combined block- and individual drive device, individually linear-motor-driven pipetting ducts are also known, each of which comprises a separately operable rotor, a plurality or even all of the rotors running on a shared stator. These pipetting ducts, or generally speaking these linear movement units, can be driven in a block or individually by different modes of operation of the linear-motor drives.
The subsequently published DE 10 2012 216 544.4 further discloses a combined block- and individual drive device in which a block movement transmission gear unit comprises a drive spindle extending parallel to the linear movement axis and in which each linear movement unit further comprises a spindle nut passed through by the drive spindle. In a manner known per se, in this case the linear movement units can be moved jointly as a block relative to the drive spindle along the drive spindle longitudinal axis by rotating the drive spindle about the drive spindle longitudinal axis thereof relative to the individual spindle nuts. By way of a separate drive shaft, comprising sliding blocks which are mounted rotationally engaged but axially displaceable thereon and which are in meshed engagement with the spindle nuts and coupled to the linear movement units, the linear movement units can be moved along the linear movement axis with movement relative to one another.
Combined block- and individual drive devices are advantageous in particular on pipetting devices in which pipetting ducts, arranged in succession along the movement path or linear movement axis, as the linear movement units can be moved along the movement path as a jointly movable block at a predetermined distance, without a relative change in distance. In some cases, it may be necessary to change the distance along the movement path between the individual pipetting ducts, or generally speaking the linear movement units, for example if liquid is to be pipetted out of or into a titre plate in which depressions for receiving liquid, generally known as “wells”, are at a different distance from one another from in other titre plates which are processed using the same pipetting device at different times. Individual movement of this type of the pipetting ducts, or generally speaking linear movement units, to change the distance between them along the movement path, is also referred to as “spreading movement” in the present application.